Formals of aliphatic partial ethers



Patented Apr. 7, 1936 PATENT OFFICE FORMALS OF ALIPHATIC PARTIAL ETHERS OF POLYHYDRIC ALCOHOLS AND METH- OD OF MAKING THE SAME George W. Seymour, Cumberland, Md., assignor Y to Celanese Corporation of America, a corporation of Delaware No Drawing. Original application August 23,

1932, Serial No. 630,062. Divided and this application April Claims.

This application is a division of my application No. 630,062 filed August 23, 1932.

This invention relates to solvents for cellulose acetate and other derivatives of cellulose and relates to methods and compositions wherein such solvent is employed.

' An object of my invention is to produce a'new solvent for cellulose acetate or other derivatives of cellulose; Another'object of my invention is to employ the formals of partial ethers of polyhydric alcohols assolvents for cellulose acetate or other organic derivatives of cellulose in various processes and for various compositions. Other objects of this invention will appear from the following detailed description.

As is well known, the number of substances that are solvents for cellulose acetate, especially the acetone-soluble type of cellulose acetate, is very limited. Because of the small range of these solvents, it is often dimcult and even impossible to find a solvent'thatmeets with the particular requirements of a given problem, such as boiling point, compatibility or mutual-solubility with other solvents, resins or other ingredients present in the, cellulose acetate comv position in which it is employed, cheapness, availability, etc. This is particularly true in the case of high or medium boiling solvents for cellulose acetate.

I have found that the formals of the partial ethers of polyhydric alcohols are excellent solvents for cellulose acetate, particularly the acetone-soluble cellulose acetate, and other organic derivatives of cellulose, and may be employed in all compositions and processes wherein cellulose acetate is to be dissolved.

The formals of the partial ethers of polyhydric alcohols may be considered as the methylene ethers of polyhydric alcohols in which hydrogen of at least one of the hydroxy groups has been substituted by-an alkyl, aryl or aralkyl group, and may be represented by the probable general formula R0 (CH2) nOCHzO (CH2) n'OR' wherein R and B. may be the same or different 'alkyl, aryl or aralkyl groups, and n and 11. may be the same different integers.

These formals may be prepared by the condensation of formaldehyde, formalin, trihydroxymethylene or para-formaldehyde with the partial ethers of a polyhydric alcohol in the presence of an acidic catalyst such as ferric chloride or other acid salts, hydrochloric acid, sulfuric acid, phosphoric acid or other strong subjected to'slow distillation. The

16, 1934, Serial No..720,815. In. Canada August 7, 1933 or weak mineral acids. Any suitable partial ether of a polyhydric alcohol may be employed for preparing these formals, examples of which are the monomethyl ether of ethylene glycol, the monomethyl .ether of ethylene glycol and the monomethyl or ethyl ether of propylene glycol or of diethylene glycol.

-,The term formal is herein employed to denote compounds obtainable by the condensation of formaldehyde, with the partial ethers of polyhydrio alcohols. The term formaldehyde is to be construed as covering also substances which are obvious chemical equivalents of formaldehyde, suchas formalin, trihydroxymethylene and para-formaldehyde.

The following method of preparing the formal of the monomethyl ether of ethylene glycol is illustrative of the method of preparing these formals.

Two (2) molecular proportions of the monomethyl ether of ethylene glycol, CHaOCHzCHzOH,

' one (1) molecular proportion of para-formaldehyde and hydrated ferric chloride (in amount equal to 4% of the weight'of the reactants) are distillate is collected in three fractions, namely at temperatures from 92 to 110 C., from 110 to 180 C. and from 180 to 200 C. Calcium chloride is added to the first two fractions and the upper layers thereof are added to the third fraction and the mixture is then redistilled. The fraction boiling at 197 C. to 205 C. is collected, and this is a formal which is probably represented by the formula (CHaOCHzCHzO) 2CH2 As stated, these formals may be used wherever it is desired to dissolve partially or wholly derivatives of cellulose, such as cellulose nitrate but particularly the organic derivatives of cellulose such as organic esters of cellulose and cellulose ethers. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulose butyrate, while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose.

A few of the many instances of the use of these formals will be given.

These formals may be employed alone or in conjunction with low boiling, medium, or high boiling solvents, resins both natural and synthetic, plasticizers or other desired ingredients to prepare coating compositions or dopes containing cellulose acetate or other organic derivatives of cellulose, which coating compositions may be employed for coating fabrics, wood and the like, or as lacquers containing suitable natural or synthetic resins; to be applied to metallic or other smooth surfaces. Dopes containing the cellulose acetate dissolved in a solvent comprising these formals may be cast on :to smooth surfaces such as film bands, wheels and.

the like, to form upon evaporation of the solvent, films which may be used for photographic pur- I poses, or thin foils to be employed as transparent wrappings for packages of foodstuffs, -tobacco- Y wherein R and- R'- are the same or different products and other articles of commerce.

Plastic compositions containing organic derivatives of cellulose, plasticizers andctherdesired ingredients may be-lmade by:.the;use of 1: these formals as at least part of the solventduring the kneading of the mass and subsequent working up of the same on heated malaxating;

rolls.

If desired besides the formals, other solvents may be used in addition thereto, such aslow boiling solvents like acetone, ethylene dichloride and the'like, and medium and/or high boiling solvents such as ethyl acetate, ethyl lactate, tetrachorethane or diacetone alcohol. Examples of plasticizers for cellulose acetate are diphenylol propane, phthalate, monomethylenexylene sulfonamide', triphenyl phosphate, etc. i It is to be understood that the foregoing dean acidic condensing agent.

' {5.Method 'of preparin 'trac t'n, dibut l" tartrate, diet 1' 1 e 1 y hy with formaldehyde in the,

- condensingagent.

scription is given merely by way of illustration and that many variations may be made therein without departing from fthe'spirit 'of my into secure by Letters Patent is: .41. As a new, product a compound having the eneral formu la v nomrninocmowmmon' alkyl groups and n and n are the same or different integers;

2. As-a new'product the formal of the mono "'rnethyl ether of ethylene glycol.

sias a'new 'pr'oduct, the formal of an aliphatic partial ether of a polyhydric alcohol.

4. Method of preparingh formals of partial ethers of polyhydric falcohols. comprising condensing formaldehyde, ithI an aliphatic partial ether of a polyhydric alcohol the. presence of i. SEYMOUR."-

presence ofran acidic umm -op gpomcmu; 9i

Patent No, 2036,504, I H I I w I It is'hereby certified tha terrior-appears in the p r-ihted'speoi-fioatio of the above numbered patent requiring oorrection'as 'foll c'jws'ti' Palge""l, "first column, line 48,: after seme"..inse'rtor; and that the hsaLid Letters Patent should be read with this' correction "therein thatthe same may conform to the record of the case'. in the Patent Office.

Signed and sealed this 12th dayof May, A. D. 1936.

Leslie Fraze r' I (Seal) Acting Commissioner of Patents. 

